BJFE / BearFoot fx Guitar Effects Community

Nice

I'm thinking that maybe the schottky diode and 100 ohm resistor in the power-supply of the Paradigm might be contributing to the low dip in the LFO. You can tilt the LFO towards the "ON" side with the dwell control, of course. But the "ON" side also tends to have a bit of saturation where the LEDs reach their maximum brightness and don't get any brighter.

Try this, though; it doesn't require any circuit mod... Run an 18v power supply (mind the polarity; it still has to have the negative tip). Then you'll have to turn the dwell control all the way down to get the LFO to dip to the "OFF" side at all; but the LEDs will have a brighter maximum "ON" side, too; so this should increase the dynamic range of the LFO and rest less at the top and bottom of the cycle.

Let me know if this works out for you...

Okay; so to smooth out the sweep, I've decreased the resistor value that feeds the LFO some bias current from the Dwell control (much stronger control over the dwell; can keep the LEDs from turning all the way off at clockwise now), and I've increased, slightly, the resistors in-line with the LDRs to emphasize and round out/slow down the curve in the lower part of the sweep in the phase-shift sections.

All new ones from now on will feature this tweak, and I can retrofit yours if you want a more gentle feel to your warble.

skreddy wrote:Okay; so to smooth out the sweep, I've decreased the resistor value that feeds the LFO some bias current from the Dwell control (much stronger control over the dwell; can keep the LEDs from turning all the way off at clockwise now), and I've increased, slightly, the resistors in-line with the LDRs to emphasize and round out/slow down the curve in the lower part of the sweep in the phase-shift sections.

All new ones from now on will feature this tweak, and I can retrofit yours if you want a more gentle feel to your warble.

Marc,
Is it still able to get the original sweep ---- that is really what sets this type of modulation apart is how it fits with your rig and since there is such a wide difference in speaker range , what could sound wrong on Jensens could be just right for Celestions etc...... might be good to have some LFO sweep 'gears' ~ but thats another toggle.....

Donner wrote:

skreddy wrote:Okay; so to smooth out the sweep, I've decreased the resistor value that feeds the LFO some bias current from the Dwell control (much stronger control over the dwell; can keep the LEDs from turning all the way off at clockwise now), and I've increased, slightly, the resistors in-line with the LDRs to emphasize and round out/slow down the curve in the lower part of the sweep in the phase-shift sections.

All new ones from now on will feature this tweak, and I can retrofit yours if you want a more gentle feel to your warble.

Marc,
Is it still able to get the original sweep ---- that is really what sets this type of modulation apart is how it fits with your rig and since there is such a wide difference in speaker range , what could sound wrong on Jensens could be just right for Celestions etc...... might be good to have some LFO sweep 'gears' ~ but thats another toggle.....

No; the new sweep is much improved--more gradual and consistent, much larger sweet spot and more constant movement. Nobody would need to go back. But with the Dwell control, you can still get a whumpy thing if you like; it's right there at the counter-clockwise setting.

Wish I still had it but I ended up selling it when it wasn't working for me. I'll keep my eye (ear) out for new clips and if I hear something that sounds like it'll work for me I'll pick another one up direct

Thanks Marc!

cajone5 wrote:Wish I still had it but I ended up selling it when it wasn't working for me. I'll keep my eye (ear) out for new clips and if I hear something that sounds like it'll work for me I'll pick another one up direct

Thanks Marc!

I didn't get completely away from the Uni-Vibe's characteristic fast transition; I just trimmed the amount by which the sweep over-shoots the top end. Because in my circuit, once the sweep passes a certain point, there's really nothing more to achieve in terms of changing to a different sound.

But if you're looking for something with a gradual moving filter sweep that never stops moving at the same constant speed, you'll want something in more of a phaser design like the MXR Phase 90 for example.

Good news: Finally re-visited this circuit with the goal of getting its sweep more triangle/Phase 90-ish. Was stupidly simple.
Change C12 from .12uf to .01uf (filters the LFO a bit less roundly)
Also change R29 from 820R to 2.7k (keeps the LEDs from over-saturating)

I suppose I should just start making them like this from now on. A bit less "Uni-Vibe"ish but I think much more useful.

skreddy wrote:Good news: Finally re-visited this circuit with the goal of getting its sweep more triangle/Phase 90-ish. Was stupidly simple.
Change C12 from .12uf to .01uf (filters the LFO a bit less roundly)
Also change R29 from 820R to 2.7k (keeps the LEDs from over-saturating)

I suppose I should just start making them like this from now on. A bit less "Uni-Vibe"ish but I think much more useful.

SoCal tourbox, Mr. Skreddy? I would demo it!

Cheers.

skreddy wrote:Good news: Finally re-visited this circuit with the goal of getting its sweep more triangle/Phase 90-ish. Was stupidly simple.
Change C12 from .12uf to .01uf (filters the LFO a bit less roundly)
Also change R29 from 820R to 2.7k (keeps the LEDs from over-saturating)

I suppose I should just start making them like this from now on. A bit less "Uni-Vibe"ish but I think much more useful.